Apparatus and method for controlling cooling fan of vehicle

ABSTRACT

An apparatus and a method for controlling a cooling fan of a vehicle are capable of preventing a fan motor from being damaged by locking the fan motor in cold weather conditions. The apparatus includes: a fan motor driving the cooling fan; and a controller generating an operation signal for controlling the cooling fan and providing the operation signal to the fan motor, where the controller confirms an ignition-off time for which an ignition was turned off when the ignition is turned on, confirms a change rate of an air conditioner refrigerant pressure for a measurement time when the ignition-off time exceeds a decision-possible time and an intake air temperature is present within a predetermined temperature, and locks the fan motor depending on the change rate of the air conditioner refrigerant pressure.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims under 35 U.S.C. §119(a) the benefit of KoreanPatent Application No. 10-2015-0167950 filed in the Korean IntellectualProperty Office on Nov. 27, 2015, the entire contents of which areincorporated herein by reference.

BACKGROUND

(a) Technical Field

The present invention relates to an apparatus for controlling a coolingfan of a vehicle, and more particularly, to an apparatus and a methodfor controlling the cooling fan capable of preventing damage to a fanmotor by locking the fan motor in cold weather conditions, such aswinter.

(b) Description of the Related Art

Since a large amount of heat is generated in an engine of a vehicle, acoolant is circulated in the vicinity of the engine in order to cool theengine, thereby lowering the temperature of the engine. A heated coolantis heat-radiated in a radiator, and a cooling fan is installed in anengine compartment of the vehicle in order to improve a heat radiationeffect of the radiator.

The cooling fan maintains a temperature of the coolant in an appropriatecondition to prevent overheat of the engine and allow performance of theengine to be optimized. The cooling fan is primarily driven by a motor.

In cold weather conditions, moisture or snow is introduced into thecooling fan, such that freezing of the cooling fan often occurs.Therefore, at the time of the freezing of the cooling fan, the coolingfan is not operated even in a condition in which the cooling fan isturned on.

In such conditions, the cooling fan is not generally operated. However,when a driver presses a defrost button in order to remove fog or frost,an air conditioner is operated, such that an air conditioner refrigerantpressure gradually rises. When the air conditioner refrigerant pressurereaches a predetermined pressure, it arrives at a region in which thecooling fan should be operated. However, the cooling fan is not operateddue to locking of the motor caused by the freezing of the cooling fan.In addition, when a locking time becomes long, the motor may be damagedor, in extreme circumstances, a fire may occur in the enginecompartment.

When an external temperature sensor is present in the vehicle, it ispossible that the cooling fan is not operated at sub-zero temperatures.However, when an external temperature sensor is not mounted in thevehicle, an external temperature may not be checked, such that a controlmay not be performed to prevent operation of the cooling fan at sub-zerotemperatures. In addition, in such a case, the cooling fan is operatedin a predetermined condition, such that the cooling fan may be frozen,thereby causing damage to the motor. The damage to the motor generatesoverheat of the engine, which can result in significant repair costs.

The above information disclosed in this Background section is only forenhancement of understanding of the background of the invention andtherefore it may contain information that does not form the prior artthat is already known in this country to a person of ordinary skill inthe art.

SUMMARY

The present invention provides an apparatus and a method for controllinga cooling fan of a vehicle capable of locking a fan motor on the basisof an intake air temperature and an air conditioner refrigerant pressurein order to prevent damage to the fan motor in cold weather conditions.

Further, the present invention provides an apparatus and a method forcontrolling a cooling fan of a vehicle capable of operating the coolingfan in the case in which a coolant temperature is greater than or equalto a reference temperature.

An exemplary embodiment of the present invention provides an apparatusfor controlling a cooling fan of a vehicle, the cooling fan beinginstalled in an engine compartment of the vehicle, including: a fanmotor driving the cooling fan; and a controller generating an operationsignal for controlling the cooling fan and providing the operationsignal to the fan motor, wherein the controller confirms an ignition-offtime for which an ignition was turned off when the ignition is turnedon, confirms a change rate of an air conditioner refrigerant pressurefor a measurement time when the ignition-off time exceeds adecision-possible time and an intake air temperature is present within apredetermined temperature, and locks the fan motor depending on thechange rate of the air conditioner refrigerant pressure.

The confirm a first change rate of the air conditioner refrigerantpressure for a first measurement time, operate the cooling fan throughthe fan motor by providing the operation signal to the fan motor for asecond measurement time, confirm a second change rate of the airconditioner refrigerant pressure for the second measurement time, andstop the operation of the cooling fan depending on the first change rateand the second change rate.

The controller may calculate a comparison value on the basis of thefirst change rate and the second change rate, decide whether or not thecomparison value is less than or equal to a decision reference, and stopthe operation of the cooling fan in the case in which the comparisonvalue is not maintained for a duration in a state in which thecomparison value is less than or equal to the decision reference.

The apparatus for controlling a cooling fan of a vehicle may furtherinclude: a state detector including at least one of an intake airtemperature measurer measuring the intake air temperature; a coolantmeasurer measuring a coolant temperature; a speed measurer measuring avehicle speed; and a pressure measurer measuring the air conditionerrefrigerant pressure.

The controller may provide the operation signal to the fan motor andlock the fan motor depending on the change rate of the air conditionerrefrigerant pressure for the measurement time, when a compressor isoperated and a vehicle speed is 0.

The controller may turn off a compressor when the intake air temperatureis not present within the predetermined temperature, and operate thecooling fan when a coolant temperature is greater than or equal to areference temperature in a state in which the controller turns off anair conditioner switch.

Another exemplary embodiment of the present invention provides a methodfor controlling a cooling fan of a vehicle by an apparatus forcontrolling a cooling fan of a vehicle, including: confirming anignition-off time for which an ignition was turned off when the ignitionis turned on; deciding whether or not the ignition-off time exceeds adecision-possible time; deciding whether or not an intake airtemperature is present within a predetermined temperature when theignition-off time exceeds the decision-possible time; and locking a fanmotor depending on a change rate of an air conditioner refrigerantpressure for a measurement time when the intake air temperature ispresent within the predetermined temperature.

In an exemplary embodiment of the present invention, it is possible toprevent the fan motor from freezing in cold weather conditions, such aswinter, and thus prevent damage by stopping operation of the fan motor.

In addition, in the case in which the coolant temperature is greaterthan or equal to the reference temperature, the cooling fan is operated,thereby making it possible to prevent overheat of the engine.

Other effects that may be obtained or are predicted by an exemplaryembodiment of the present invention will be explicitly or implicitlydescribed in a detailed description of the present invention. That is,various effects that are predicted according to an exemplary embodimentof the present invention will be described in the following detaileddescription.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing an apparatus for controlling a coolingfan of a vehicle according to an exemplary embodiment of the presentinvention.

FIG. 2 is a flow chart showing a method for controlling the cooling fanof the vehicle according to an exemplary embodiment of the presentinvention.

FIG. 3 is an illustrative view showing a control method when an airconditioner switch is turned off in the method for controlling thecooling fan of the vehicle according to an exemplary embodiment of thepresent invention.

FIG. 4 is a flow chart showing a method for detecting locking in themethod for controlling the cooling fan of the vehicle according to anexemplary embodiment of the present invention.

FIG. 5 is an illustrative view for describing the method for detectinglocking in the method for controlling the cooling fan of the vehicleaccording to an exemplary embodiment of the present invention.

FIG. 6 is an illustrative view for describing a first change rate and asecond change rate in the method for controlling the cooling fan of thevehicle according to an exemplary embodiment of the present invention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

It is understood that the term “vehicle” or “vehicular” or other similarterm as used herein is inclusive of motor vehicles in general such aspassenger automobiles including sports utility vehicles (SUV), buses,trucks, various commercial vehicles, watercraft including a variety ofboats and ships, aircraft, and the like, and includes hybrid vehicles,electric vehicles, plug-in hybrid electric vehicles, hydrogen-poweredvehicles and other alternative fuel vehicles (e.g. fuels derived fromresources other than petroleum). As referred to herein, a hybrid vehicleis a vehicle that has two or more sources of power, for example bothgasoline-powered and electric-powered vehicles.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the invention. Asused herein, the singular forms “a,” “an” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprises”and/or “comprising,” when used in this specification, specify thepresence of stated features, integers, steps, operations, elements,and/or components, but do not preclude the presence or addition of oneor more other features, integers, steps, operations, elements,components, and/or groups thereof. As used herein, the term “and/or”includes any and all combinations of one or more of the associatedlisted items. Throughout the specification, unless explicitly describedto the contrary, the word “comprise” and variations such as “comprises”or “comprising” will be understood to imply the inclusion of statedelements but not the exclusion of any other elements. In addition, theterms “unit”, “-er”, “-or”, and “module” described in the specificationmean units for processing at least one function and operation, and canbe implemented by hardware components or software components andcombinations thereof.

Further, the control logic of the present invention may be embodied asnon-transitory computer readable media on a computer readable mediumcontaining executable program instructions executed by a processor,controller or the like. Examples of computer readable media include, butare not limited to, ROM, RAM, compact disc (CD)-ROMs, magnetic tapes,floppy disks, flash drives, smart cards and optical data storagedevices. The computer readable medium can also be distributed in networkcoupled computer systems so that the computer readable media is storedand executed in a distributed fashion, e.g., by a telematics server or aController Area Network (CAN).

Hereinafter, an operation principle of an apparatus and a method forcontrolling a cooling fan of a vehicle according to an exemplaryembodiment of the present invention will be described in more detailwith reference to the accompanying drawings.

However, drawings provided below and a detailed description to beprovided below relate to one preferred exemplary embodiment of severalexemplary embodiments for effectively describing features of the presentinvention. Therefore, the present invention is not limited to only thefollowing drawings and description.

Hereinafter, an exemplary embodiment of the present invention will bedescribed in detail with reference to the accompanying drawings.

FIG. 1 is a block diagram showing an apparatus for controlling a coolingfan of a vehicle according to an exemplary embodiment of the presentinvention.

The apparatus 50 for controlling a cooling fan of a vehicle includes astate detector 100, a controller 110, an air conditioner switch 120, acompressor 125, a relay 130, a connector 140, a blower assembly 150, anda cooling fan 160.

The state detector 100 detects information required in order to controlthe cooling fan 160. The state detector 100 includes an intake airtemperature measurer 102, a speed measurer 104, a pressure measurer 106,and a coolant temperature measurer 108.

The intake air temperature measurer 102 measures an intake airtemperature, which is a temperature of air introduced into the vehicle,and provides the measured temperature to the controller.

The speed measurer 104 measure a vehicle speed, which is a speed of thevehicle, and provides the measured vehicle speed to the controller.

The pressure measurer 106 measures an air conditioner refrigerantpressure, and provides the measured air conditioner refrigerant pressureto the controller.

The coolant temperature measurer 108 measures a coolant temperature ofan engine, and provides the measured coolant temperature to thecontroller.

The controller 110 controls at least one of the state detector 100, theair conditioner switch 120, the compressor 125, the relay 130, theconnector 140, the blower assembly 150, and the cooling fan 160, whichare components of the apparatus 50 for controlling a cooling fan of avehicle, in order to operate or stop the cooling fan 160.

The controller 110 confirms an ignition-off time for which an ignitionwas turned off when the ignition is turned on. The controller 110confirms a change rate of the air conditioner refrigerant pressure for ameasurement time when the ignition-off time exceeds a decision-possibletime and the intake air temperature is present within a predeterminedtemperature. The controller 110 performs a control to lock or normallyoperate a fan motor 157 depending on the change rate of the airconditioner refrigerant pressure. A method for controlling the coolingfan 160 in the controller 110 will be described in more detail withreference to FIGS. 2 to 5.

For this purpose, the controller 110 may be implemented by at least oneprocessor operated by a predetermined program, which may be programmedto perform the respective steps of a method for controlling a coolingfan of a vehicle according to an exemplary embodiment of the presentinvention.

The air conditioner switch 120 turns on or turns off an air conditioner.That is, the air conditioner switch 120 may turn on or turn off the airconditioner by a driver or the controller 110.

The compressor 125 compresses a refrigerant at a high temperature and ahigh pressure to operate the air conditioner, when the air conditioneris turned on by the air conditioner switch 120.

The relay 130 provides an operation signal to the connector 140depending on a control of the controller 110.

The connector 140 receives the operation signal from the relay 130 todrive the fan motor 157. To this end, the connector 140 includes a highspeed connector 143, a low speed connector 146, and a ground connector149. The high speed connector 143 is directly connected to the fan motor157, and the low speed connector 146 is connected to the fan motor 157through a resistor 153. The ground connector 149 is connected to the fanmotor 157 and a ground. Here, the high speed connector 143, the lowspeed connector 146, and the ground connector 149 may also be formed ofa switch. The connector 140 drives the fan motor 157 through the lowspeed connector 146 and the resistor 153 when it receives a low speedoperation signal from the relay 130. In addition, the connector 140drives the fan motor 157 through the high speed connector 143 when itreceives a high speed operation signal from the relay 130.

The blower assembly 150 includes the fan motor 157 and the resistor 153.

The fan motor 157 rotates blades included in the cooling fan 160 tooperate the cooling fan 160.

The resistor 153 adjusts a speed of the fan motor 157. That is, thelarger the resistance value of the resistor 153, the lower the speed atwhich the fan motor 157 is driven.

The cooling fan 160 is driven by the fan motor 157 included in theblower assembly 150. The cooling fan 160 maintains a temperature of acoolant in an appropriate condition to prevent overheat of the engineand allow performance of the engine to be optimally exhibited.

Hereinafter, a method for controlling a cooling fan 160 in a vehicleaccording to an exemplary embodiment of the present invention will bedescribed with reference to FIGS. 2 to 6.

FIG. 2 is a flow chart showing a method for controlling the cooling fanof the vehicle according to an exemplary embodiment of the presentinvention.

Referring to FIG. 2, the controller 110 confirms whether or not theignition is turned on (S210). Here, the controller 110 may confirmwhether or not the ignition is turned on by receiving an ignition-onsignal from an initial detector (not shown).

The controller 110 confirms the ignition-off time for which the ignitionwas turned off (S215). That is, the controller 110 may confirm theignition-off time by counting a time for which the ignition was turnedoff before the ignition is turned on.

The controller 110 decides whether or not the ignition-off time exceedsthe decision-possible time (S220). Here, the decision-possible time mayindicate a reference time for deciding that the vehicle is parked in thenight, and may be set by a worker or be set through a predefinedalgorithm (for example, a program or a probability model). For example,the decision-possible time may be six hours.

The reason for deciding whether or not the ignition-off time exceeds thedecision-possible time as described above is to confirm that the vehiclewas parked in the night. In the case in which the vehicle is parked inthe night, it may be assumed that an intake air temperature and anexternal air temperature are the same as each other. Therefore, damageto the fan motor 157 may be prevented using the intake air temperaturewithout using an external air temperature sensor.

The controller 110 confirms the intake air temperature (S225) when theignition-off time exceeds the decision-possible time. Here, the intakeair temperature may be a temperature measured through the intake airtemperature measurer when the ignition of the vehicle is turned off.

The controller 110 decides whether or not the intake air temperature ispresent within a predetermined temperature (S230). That is, thecontroller 110 may decide whether or not the intake air temperature isless than or equal to a maximum temperature, and greater than or equalto a minimum temperature. Here, the maximum temperature and the minimumtemperature indicate reference temperatures for deciding a temperatureat which the cooling fan 160 may be frozen, and may be set by a workeror be set through a predefined algorithm (for example, a program or aprobability model). For example, the maximum temperature may be 7° C.,and the minimum temperature may be −10° C.

The controller 110 decides whether or not the compressor 125 is operated(S235) when the intake air temperature is present within thepredetermined temperature. That is, the controller 110 may decidewhether the compressor 125 is in a turn-on state or a turn-off statewhen the intake air temperature is greater than or equal to the minimumtemperature and is less than or equal to the maximum temperature.

The controller 110 decides whether or not a vehicle speed is 0 (S240)when the compressor 125 is operated. That is, the controller 110confirms the vehicle speed provided from the speed measurer when thecompressor 125 is operated. The controller 110 decides whether or notthe vehicle speed is 0 to decide whether or not the vehicle is in anidle state. In addition, the controller 110 generates an operationsignal for operating the cooling fan 160 when the vehicle speed is 0.Here, the operation signal may be a low speed operation signal foroperating the cooling fan 160 at a low speed.

The controller 110 performs locking detection for whether to lock ornormally operate the fan motor 157 (S245). A method for detectinglocking of the fan motor will be described in detail with reference toFIG. 4.

The controller 110 decides whether or not a locking detection result isnormal (S250).

The controller 110 stops an operation of the cooling fan 160 (S255) whenthe locking detection result is not normal. That is, the controller 110stops the operation of the cooling fan 160 and stops an operation of thecompressor 125 when the locking detection result is locking.

Meanwhile, the controller 110 moves to S275 to operate the cooling fan160, when the locking detection result is normal. Here, since a methodfor controlling the cooling fan 160 that is normal is the same as orsimilar to a method for controlling the cooling fan 160 that isgenerally used, a detailed description therefor will be omitted.

The controller 110 confirms whether or not the ignition is turned off(S260). That is, the controller 110 may complete the control of thecooling fan when the ignition is turned off.

Meanwhile, the controller 110 confirms the immediately previous state ofthe cooling fan (S265) when the ignition-off time is less than or equalto the decision-possible time. That is, since the controller 110 maydecide that the vehicle is not parked in the night when the ignition-offtime is less than or equal to the decision-possible time, a state of thecooling fan 160 that was decided by previously turning on the ignitionis confirmed.

The controller 110 decides whether or not the immediately previous stateof the cooling fan is normal (S270).

The controller 110 operates the cooling fan 160 (S275) when theimmediately previous state of the cooling fan is normal. In addition,the controller 110 may normally drive the cooling fan 160 since it isnot severe cold when the intake air temperature exceeds the maximumtemperature. Then, the controller 110 may confirm that the ignition isturned off.

Meanwhile, the controller 110 turns off the compressor 125 (S280) whenthe intake air temperature is less than the minimum temperature.

The controller 110 turns off the air conditioner switch 120 (S285) whenthe compressor 125 is not operated as a confirmation result in S235, thevehicle speed is not 0 as a decision result in S240, or the controller110 turns off the compressor 125 in S280.

The controller 110 confirms a coolant temperature (S290). That is, thecontroller 110 receives the coolant temperature provided from thecoolant temperature measurer 108 in order to control the cooling fan 160and confirms the received coolant temperature, when the air conditionerswitch 120 is turned off. The controller 110 decides whether or not thecoolant temperature is greater than or equal to a reference temperature.

The controller 110 operates the cooling fan 160 (S295) when the coolanttemperature is greater than or equal to the reference temperature. Thatis, the controller 110 may lower a temperature of the engine byoperating the cooling fan 160 when the coolant temperature is greaterthan or equal to the reference temperature, in order to prevent overheatof the engine. Here, the reference temperature indicates a referencetemperature for deciding whether or not the overheat is generated in theengine, and may be a predetermined value. For example, as shown in FIG.3, the reference temperature 310 may be 105° C.

The controller 110 provides the operation signal to the fan motor 157through the relay 130 and the connector 140, and operates the coolingfan 160 through the fan motor 157. Here, the operation signal is a highspeed operation signal 320. Therefore, the cooling fan 160 is operatedat a high speed, thereby making it possible to lower the temperature ofthe engine.

FIG. 4 is a flow chart showing a method for detecting locking in themethod for controlling the cooling fan of the vehicle according to anexemplary embodiment of the present invention, FIG. 5 is an illustrativeview for describing the method for detecting locking in the method forcontrolling the cooling fan of the vehicle according to an exemplaryembodiment of the present invention, and FIG. 6 is an illustrative viewfor describing a first change rate and a second change rate in themethod for controlling the cooling fan of the vehicle according to anexemplary embodiment of the present invention.

Referring to FIGS. 4 to 6, the controller 110 confirms a first changerate of the air conditioner refrigerant pressure for a first measurementtime (S410). Here, the first measurement time may indicate a timedelayed when the operation signal is transmitted from the controller 110to the fan motor 157 through the relay 130 and the connector 140. Thereason for delaying and then transmitting the operation signal in thecontroller 110 as described above is to prevent bugs from beinggenerated in the relay 130, the connector 140, and the like. Here, asshown in FIG. 5, the first measurement time 510 may be a time from 0second to a first time. For example, the first time may be 0.5 second.

In other words, the controller 110 receives a first air conditionerrefrigerant pressure provided from the pressure measurer 106 at 0second, and receives a second air conditioner refrigerant pressureprovided from the pressure measurer 106 at the first time. Thecontroller 110 calculates the first change rate on the basis of thefirst air conditioner refrigerant pressure and the second airconditioner refrigerant pressure. Here, the first change rate may berepresented by a gradient 610, as shown in FIG. 6.

The controller 110 operates the cooling fan 160 for a second measurementtime (S420). In other words, the controller 110 provides the operationsignal to the relay 130 at the first time, and the relay 130 providesthe operation signal to the connector 140. Here, the operation signalmay be a low speed operation signal. The low speed connector 146 of theconnector 140 drives the fan motor 157 through the resistor 153 when thelow speed operation signal is received. Therefore, the cooling fan 160may be operated by the fan motor 157.

Here, as shown in FIG. 5, the second measurement time 530 may indicate atime for which the cooling fan 160 is operated, and may be apredetermined value. The second measurement time 530 may be a time fromthe first time to a second time. For example, the second time may be 3.5seconds.

The controller 110 stops the operation of the cooling fan 160 at thesecond time(S430).

The controller 110 confirms a second change rate of the air conditionerrefrigerant pressure for the second measurement time (S440). In otherwords, the controller 110 receives a third air conditioner refrigerantpressure provided from the pressure measurer 106 at the first time, andreceives a fourth air conditioner refrigerant pressure provided from thepressure measurer 106 at the second time. The controller 110 calculatesthe second change rate on the basis of the third air conditionerrefrigerant pressure and the fourth air conditioner refrigerantpressure. Here, the second change rate may be represented by a gradient630, as shown in FIG. 6.

The controller 110 decides whether or not a total measurement timeexceeds a reference time (S450). That is, the controller 110 adds thefirst measurement time and the second measurement time to each other togenerate the total measurement time, and decides whether or not thetotal measurement time exceeds the reference time.

The controller 110 decides whether or not a comparison value is lessthan or equal to a decision reference (S460). In detail, the controller110 calculates the comparison value on the basis of the first changerate and the second change rate. That is, the controller 110 maycalculate the comparison value through equation 1.

C=B/A  [equation 1]

Here, C may indicate the comparison value, A may indicate the firstchange rate, and B may indicate the second change rate.

The controller 110 decides whether or not the comparison value is lessthan or equal to the decision reference (S460). Here, the decisionreference is a reference value for deciding whether to normally operatethe fan motor 157 or lock the fan motor 157. For example, the decisionreference may be 0.7.

The controller 110 decides whether or not the comparison value ismaintained for a duration in a state in which the comparison value isless than or equal to the decision reference (S470). For example, theduration may be 2 seconds.

The controller 110 decides that the cooling fan 160 is normal (S480)when the comparison value is maintained for the duration in the state inwhich the comparison value is less than or equal to the decisionreference.

The controller 110 decides that the fan motor 157 is locked (S490) inthe case in which the comparison value exceeds the decision reference orthe comparison value is not maintained for the duration in the state inwhich the comparison value is less than or equal to the decisionreference.

As described above, the apparatus 50 for controlling a cooling fan of avehicle according to an exemplary embodiment of the present inventiondecides whether or not cold weather conditions (e.g., winter) arepresent on the basis of the intake air temperature of air introducedfrom the outside into the vehicle when the ignition-off time exceeds thedecision-possible time. In cold weather conditions, the apparatus 50 forcontrolling the cooling fan confirms the change rate of the airconditioner refrigerant pressure to lock the fan motor 157, therebymaking it possible to prevent damage to the fan motor.

While this invention has been described in connection with what ispresently considered to be practical exemplary embodiments, it is to beunderstood that the invention is not limited to the disclosedembodiments, but, on the contrary, is intended to cover variousmodifications and equivalent arrangements included within the spirit andscope of the appended claims.

What is claimed is:
 1. An apparatus for controlling a cooling fan of avehicle, the cooling fan being installed in an engine compartment of thevehicle, comprising: a fan motor driving the cooling fan; and acontroller generating an operation signal for controlling the coolingfan and providing the operation signal to the fan motor, wherein thecontroller confirms an ignition-off time for which an ignition wasturned off when the ignition is turned on, confirms a change rate of anair conditioner refrigerant pressure for a measurement time when theignition-off time exceeds a decision-possible time and an intake airtemperature is present within a predetermined temperature, and locks thefan motor depending on the change rate of the air conditionerrefrigerant pressure.
 2. The apparatus of claim 1, wherein: thecontroller confirms a first change rate of the air conditionerrefrigerant pressure for a first measurement time, operates the coolingfan through the fan motor by providing the operation signal to the fanmotor for a second measurement time, confirms a second change rate ofthe air conditioner refrigerant pressure for the second measurementtime, and stops the operation of the cooling fan depending on the firstchange rate and the second change rate.
 3. The apparatus of claim 2,wherein: the controller calculates a comparison value on the basis ofthe first change rate and the second change rate, decides whether or notthe comparison value is less than or equal to a decision reference, andstops the operation of the cooling fan in the case in which thecomparison value is not maintained for a duration in a state in whichthe comparison value is less than or equal to the decision reference. 4.The apparatus of claim 1, further comprising: a state detector includingat least one of: an intake air temperature measurer measuring the intakeair temperature, a coolant measurer measuring a coolant temperature, aspeed measurer measuring a vehicle speed, and a pressure measurermeasuring the air conditioner refrigerant pressure.
 5. The apparatus ofclaim 1, wherein: the controller provides the operation signal to thefan motor and locks the fan motor depending on the change rate of theair conditioner refrigerant pressure for the measurement time, when acompressor is operated and a vehicle speed is
 0. 6. The apparatus ofclaim 1, wherein: the controller turns off a compressor when the intakeair temperature is not present within the predetermined temperature, andoperates the cooling fan when a coolant temperature is greater than orequal to a reference temperature in a state in which the controllerturns off an air conditioner switch.
 7. A method for controlling acooling fan of a vehicle, comprising: confirming, by a controller, anignition-off time for which an ignition was turned off when the ignitionis turned on; deciding, by the controller, whether or not theignition-off time exceeds a decision-possible time; deciding, by thecontroller, whether or not an intake air temperature is present within apredetermined temperature when the ignition-off time exceeds thedecision-possible time; and locking a fan motor, by the controller,depending on a change rate of an air conditioner refrigerant pressurefor a measurement time when the intake air temperature is present withinthe predetermined temperature.
 8. The method of claim 7, wherein thelocking of the fan motor includes: confirming a first change rate of theair conditioner refrigerant pressure for a first measurement time;operating the cooling fan for a second measurement time; confirming asecond change rate of the air conditioner refrigerant pressure for thesecond measurement time; and stopping the operation of the cooling fandepending on the first change rate and the second change rate.
 9. Themethod of claim 8, wherein the stopping of the operation of the coolingfan depending on the first change rate and the second change rateincludes: calculating a comparison value on the basis of the firstchange rate and the second change rate; deciding whether or not thecomparison value is less than or equal to a decision reference; decidingwhether or not the comparison value is maintained for a duration in astate in which the comparison value is less than or equal to thedecision reference; and stopping the operation of the cooling fan in thecase in which the comparison value is not maintained for the duration.10. The method of claim 9, wherein the comparison value is calculatedthrough an equation:C=B/A where C is the comparison value, A is the first change rate, and Bis the second change rate.
 11. The method of claim 7, wherein thelocking of the fan motor depending on the change rate of the airconditioner refrigerant pressure for the measurement time when theintake air temperature is present within the predetermined temperatureincludes: deciding whether or not a compressor is operated when theintake air temperature is present within the predetermined temperature;deciding whether or not a vehicle speed is 0 when the compressor isoperated; and locking the fan motor depending on the change rate of theair conditioner refrigerant pressure for the measurement time when thevehicle speed is
 0. 12. The method of claim 7, wherein the deciding ofwhether or not the intake air temperature is present within thepredetermined temperature includes: deciding whether or not the intakeair temperature is less than a maximum temperature; and deciding whetheror not the intake air temperature is greater than or equal to a minimumtemperature when the intake air temperature is less than the maximumtemperature.
 13. The method of claim 7, wherein, after the deciding ofwhether or not the intake air temperature is present within thepredetermined temperature, further comprising: turning off a compressorwhen the intake air temperature is not present within the predeterminedtemperature; measuring a coolant temperature in a state in which an airconditioner switch is turned off; and operating the cooling fan when thecoolant temperature is greater than or equal to a reference temperature.14. A non-transitory computer readable medium containing programinstructions executed by a processor, the computer readable mediumcomprising: program instructions that confirm an ignition-off time forwhich an ignition was turned off when the ignition is turned on; programinstructions that decide whether or not the ignition-off time exceeds adecision-possible time; program instructions that decide whether or notan intake air temperature is present within a predetermined temperaturewhen the ignition-off time exceeds the decision-possible time; andprogram instructions that lock a fan motor depending on a change rate ofan air conditioner refrigerant pressure for a measurement time when theintake air temperature is present within the predetermined temperature.